aboutsummaryrefslogtreecommitdiffstats
path: root/src/db/upnp/Discovery.cxx
blob: 8b88a0251ba62b4e1a8350efb45e1ea8a5df6e28 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
/*
 * Copyright (C) 2003-2014 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "Discovery.hxx"
#include "Device.hxx"
#include "Domain.hxx"
#include "ContentDirectoryService.hxx"
#include "WorkQueue.hxx"
#include "upnpplib.hxx"
#include "thread/Mutex.hxx"

#include <upnp/upnp.h>
#include <upnp/upnptools.h>

#include <string.h>

#include <map>

// The service type string we are looking for.
static const char *const ContentDirectorySType = "urn:schemas-upnp-org:service:ContentDirectory:1";

// We don't include a version in comparisons, as we are satisfied with
// version 1
gcc_pure
static bool
isCDService(const char *st)
{
	const size_t sz = strlen(ContentDirectorySType) - 2;
	return memcmp(ContentDirectorySType, st, sz) == 0;
}

// The type of device we're asking for in search
static const char *const MediaServerDType = "urn:schemas-upnp-org:device:MediaServer:1";

gcc_pure
static bool
isMSDevice(const char *st)
{
	const size_t sz = strlen(MediaServerDType) - 2;
	return memcmp(MediaServerDType, st, sz) == 0;
}

/**
 * Each appropriate discovery event (executing in a libupnp thread
 * context) queues the following task object for processing by the
 * discovery thread.
 */
struct DiscoveredTask {
	bool alive;
	std::string url;
	std::string deviceId;
	int expires; // Seconds valid

	DiscoveredTask(bool _alive, const Upnp_Discovery *disco)
		: alive(_alive), url(disco->Location),
		  deviceId(disco->DeviceId),
		  expires(disco->Expires) {}

};
static WorkQueue<DiscoveredTask *> discoveredQueue("DiscoveredQueue");

// Descriptor for one device having a Content Directory service found
// on the network.
class ContentDirectoryDescriptor {
public:
	ContentDirectoryDescriptor(const std::string &url,
				   const std::string &description,
				   time_t last, int exp)
		:device(url, description), last_seen(last), expires(exp+20) {}
	UPnPDevice device;
	time_t last_seen;
	int expires; // seconds valid
};

// A ContentDirectoryPool holds the characteristics of the servers
// currently on the network.
// The map is referenced by deviceId (==UDN)
// The class is instanciated as a static (unenforced) singleton.
class ContentDirectoryPool {
public:
	Mutex m_mutex;
	std::map<std::string, ContentDirectoryDescriptor> m_directories;
};

static ContentDirectoryPool contentDirectories;

// Worker routine for the discovery queue. Get messages about devices
// appearing and disappearing, and update the directory pool
// accordingly.
static void *
discoExplorer(void *)
{
	auto &mutex = contentDirectories.m_mutex;
	auto &directories = contentDirectories.m_directories;

	for (;;) {
		DiscoveredTask *tsk = 0;
		if (!discoveredQueue.take(tsk)) {
			discoveredQueue.workerExit();
			return (void*)1;
		}

		const ScopeLock protect(mutex);
		if (!tsk->alive) {
			// Device signals it is going off.
			auto it = directories.find(tsk->deviceId);
			if (it != directories.end()) {
				directories.erase(it);
			}
		} else {
			// Device signals its existence and well-being. Perform the
			// UPnP "description" phase by downloading and decoding the
			// description document.
			char *buf;
			// LINE_SIZE is defined by libupnp's upnp.h...
			char contentType[LINE_SIZE];
			int code = UpnpDownloadUrlItem(tsk->url.c_str(), &buf, contentType);
			if (code != UPNP_E_SUCCESS) {
				continue;
			}
			std::string sdesc(buf);

			// Update or insert the device
			ContentDirectoryDescriptor d(tsk->url, sdesc,
						     time(0), tsk->expires);
			if (!d.device.ok) {
				continue;
			}

#if defined(__clang__) || GCC_CHECK_VERSION(4,8)
			auto e = directories.emplace(tsk->deviceId, d);
#else
			auto e = directories.insert(std::make_pair(tsk->deviceId, d));
#endif
			if (!e.second)
				e.first->second = d;
		}
		delete tsk;
	}
}

// This gets called for all libupnp asynchronous events, in a libupnp
// thread context.
// Example: ContentDirectories appearing and disappearing from the network
// We queue a task for our worker thread(s)
static int
cluCallBack(Upnp_EventType et, void *evp)
{
	switch (et) {
	case UPNP_DISCOVERY_SEARCH_RESULT:
	case UPNP_DISCOVERY_ADVERTISEMENT_ALIVE:
		{
			Upnp_Discovery *disco = (Upnp_Discovery *)evp;
			if (isMSDevice(disco->DeviceType) ||
			    isCDService(disco->ServiceType)) {
				DiscoveredTask *tp = new DiscoveredTask(1, disco);
				if (discoveredQueue.put(tp))
					return UPNP_E_FINISH;
			}
			break;
		}

	case UPNP_DISCOVERY_ADVERTISEMENT_BYEBYE:
		{
			Upnp_Discovery *disco = (Upnp_Discovery *)evp;

			if (isMSDevice(disco->DeviceType) ||
			    isCDService(disco->ServiceType)) {
				DiscoveredTask *tp = new DiscoveredTask(0, disco);
				if (discoveredQueue.put(tp))
					return UPNP_E_FINISH;
			}
			break;
		}

	default:
		// Ignore other events for now
		break;
	}

	return UPNP_E_SUCCESS;
}

void
UPnPDeviceDirectory::expireDevices()
{
	const ScopeLock protect(contentDirectories.m_mutex);
	auto &directories = contentDirectories.m_directories;
	time_t now = time(0);
	bool didsomething = false;

	for (auto it = directories.begin();
	     it != directories.end();) {
		if (now - it->second.last_seen > it->second.expires) {
			it = directories.erase(it);
			didsomething = true;
		} else {
			it++;
		}
	}

	if (didsomething)
		search();
}

UPnPDeviceDirectory::UPnPDeviceDirectory(LibUPnP *_lib)
	:lib(_lib), m_searchTimeout(2), m_lastSearch(0)
{
	if (!discoveredQueue.start(1, discoExplorer, 0)) {
		error.Set(upnp_domain, "Discover work queue start failed");
		return;
	}

	lib->SetHandler([](Upnp_EventType type, void *event){
			cluCallBack(type, event);
		});

	search();
}

bool
UPnPDeviceDirectory::search()
{
	time_t now = time(0);
	if (now - m_lastSearch < 10)
		return true;
	m_lastSearch = now;

	// We search both for device and service just in case.
	int code = UpnpSearchAsync(lib->getclh(), m_searchTimeout,
				   ContentDirectorySType, lib);
	if (code != UPNP_E_SUCCESS) {
		error.Format(upnp_domain, code,
			     "UpnpSearchAsync() failed: %s",
			     UpnpGetErrorMessage(code));
		return false;
	}

	code = UpnpSearchAsync(lib->getclh(), m_searchTimeout,
			       MediaServerDType, lib);
	if (code != UPNP_E_SUCCESS) {
		error.Format(upnp_domain, code,
			     "UpnpSearchAsync() failed: %s",
			     UpnpGetErrorMessage(code));
		return false;
	}

	return true;
}

bool
UPnPDeviceDirectory::getDirServices(std::vector<ContentDirectoryService> &out)
{
	if (!ok())
		return false;

	// Has locking, do it before our own lock
	expireDevices();

	const ScopeLock protect(contentDirectories.m_mutex);
	auto &directories = contentDirectories.m_directories;

	for (auto dit = directories.begin();
	     dit != directories.end(); dit++) {
		for (const auto &service : dit->second.device.services) {
			if (isCDService(service.serviceType.c_str())) {
				out.emplace_back(dit->second.device, service);
			}
		}
	}

	return true;
}

bool
UPnPDeviceDirectory::getServer(const char *friendlyName,
			       ContentDirectoryService &server)
{
	std::vector<ContentDirectoryService> ds;
	if (!getDirServices(ds)) {
		return false;
	}

	for (const auto &i : ds) {
		if (strcmp(friendlyName, i.getFriendlyName()) == 0) {
			server = i;
			return true;
		}
	}

	return false;
}